Max external display resolution on 2011 MBP dGPU?

Considering the un-ending delays in the new MacBook pros, I'm coming up at an inconvenient time to be replacing my monitors.

System is a CTO 2011 2.3GHz, AMD 6750M 1GB dGPU, matte screen 1680x1050. 16GB RAM, TB SSD .. most of which doesn't matter as much as the dGPU and Thunderbolt 1 port.

I don't have a dire 'need' for 4K, but do put QHD (2560x1440) to good use - picked up a BenQ 27" for one of my pair of work displays, subsequently had DisplayPort issues with it, so am replacing that with a ViewSonic but also considering 'final configuration' for both work and at home.

I've tried without much success to confirm if I can drive a LG 34UM88-P 34" or similar UltraWide QHD display (3440x1440), while I'd continue to use USB displayport to drive a second 1080P display?

For anyone following along, the 27" QHD display is nearly perfect for 'getting work done' and font sizing, etc...for me, but I fairly often have to zoom in when showing the screen to someone..I have a feeling 30" is in the sweet spot overall for QHD, but the only thing close is the ultrawides...while I don't see any huge need for 4K at the moment for productivity (office Apps, Dev tools, terminals, web, ...), and my 2011 can't do 4K regardless even IF I was assured I could scale downwards (to likely QHD) with high quality on the panel..somewhat doubtful.

I wouldn't mind picking up a UW QHD single display for now, then a second one whenever Apple gets around to releasing a compelling MBP 'upgrade' and driving a pair of UW QHD panels.

I'm unaware of any reliable eGPU solutions at this point, not to mention what will become a port change from TB -> USB-C on my next system upgrade, so more interested in if a 2011 non-retina w/dGPU can drive a ultra wide QHD.
?

Anything up to 1600p will work fine including ultrawide at 60fps, however 4K will be lucky to get 30hz and no lag due to the bandwidth limitations of thunderbolt 1 display port implementation.

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This is what I was looking for, or nearly so - plus never know whether or not Apples GPU or implementation limits anything..
How about 1 3160-x1440p TB + 1 1080p (or 1920x1200) via USB?

That's the 'mid-term' solution I'm looking at most, as it would be the single 34" 3160x1440p plus an existing screen, as I doubt it'll pull off a pair of them nicely with one driven via USB (only single TB/mini-DP on the 2011 :-/ ), but would upgrade to a second 3160x2160 in the future once I upgrade MBPs to a more modern variety.

Should be able to do TB and USB -> HDMI or DP, though I don't know max res with this combo. Which is what I'm trying to find out.

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If you want 60hz on 4K you need DP 1.2 which thunderbolt one does not have, USB 3 does not have the bandwidth and the 2011 only had USB 2, I would imagine this will be shocking for any display over 1080p.

If you want 60hz on 4K you need DP 1.2 which thunderbolt one does not have, USB 3 does not have the bandwidth and the 2011 only had USB 2, I would imagine this will be shocking for any display over 1080p.

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I don't want 4K on it; that was everyone else's desire.

Mainly - can I run an ultrawide 2K (e.g. 3440x1440) via TB1 -> DP?

If yes (I'm running a 2560x1440 now, so know that can be done), but can I drive wider/higher horrid resolution as above and STILL drive USB(2) -> second panel? (1080p is fine)

I currently run TB1-> 27" 2560x1440 + USB(2) -> HDMI 27" 1080p. Trying to determine iff I can go to a bigger but higher res (short of 4k) for primary but also still drive the USB2 1080p panel.

- I believe I've seen that demonstrated to work, yes. Though it has nothing to do with 2K.

The capabilities of the display output in the Thunderbolt port are independent from any USB display devices you attach. They have their own maximum capabilities and don't influence each other. This is because your internal GPU isn't used with the USB adaptors which are basically small external GPUs.

- I believe I've seen that demonstrated to work, yes. Though it has nothing to do with 2K.

The capabilities of the display output in the Thunderbolt port are independent from any USB display devices you attach. They have their own maximum capabilities and don't influence each other. This is because your internal GPU isn't used with the USB adaptors which are basically small external GPUs.

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So, I believe ANY time you have an external display it's driving off the dGPU, to at least what I've seen so far.
Your comment is the logical assumption RE: driving both displays but I believe I've read some limitations around the AMD GPU, e.g. will it drive both or drop refresh to 30Hz one both, etc. etc. Thus hoping someone can confirm near identical setup before spending the $.

So, I believe ANY time you have an external display it's driving off the dGPU, to at least what I've seen so far.
Your comment is the logical assumption RE: driving both displays but I believe I've read some limitations around the AMD GPU, e.g. will it drive both or drop refresh to 30Hz one both, etc. etc. Thus hoping someone can confirm near identical setup before spending the $.

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- Well, that's the case when using the actual display output (that is, the Thunderbolt port). That runs only via the Radeon dGPU.

USB 2.0 isn't a display output, and the Radeon dGPU can't output signals through it. The various USB adaptors that exist are, in essence, external GPUs, so they bypass the GPUs of the Mac itself.

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